Polyurethane Composition for Preparing Composites

Abstract

The invention relates to a polyurethane composition for preparing composites, a polyurethane composite obtained by the preparation and a method for preparing the polyurethane composite. The polyurethane composition comprises: a) an isocyanate component; b) an isocyanate-reactive component; c) a radical reaction initiator and d) an organometallic catalyst; wherein the hydroxyl value of the component b) isocyanate-reactive component is 200 mgKOH/g to 700 mgKOH/g, and the molar ratio of isocyanate groups to hydroxyl groups of the composition is 0.6 to 1.5. The polyurethane composition of the present invention has the advantages of long pot life and simple operation process. The polyurethane composite comprising the polyurethane resin matrix prepared by the polyurethane composition of the present invention has both excellent weather resistance and mechanical strength.

1 . A polyurethane composition for preparing composites, comprising:
 a) an isocyanate component, the isocyanate component comprising not less than 97.5% by weight of an aliphatic isocyanate and optionally an aromatic isocyanate;   b) an isocyanate-reactive component, comprising:   b1) at least an organic polyol, an amount of the organic polyol being 20% by weight to 80% by weight, relative to the total weight of the isocyanate-reactive component; and   b2) at least a compound having the structure of formula I:   
       
         
           
           
               
               
           
         
         wherein R 1  is selected from hydrogen, methyl or ethyl; R 2  is selected from alkylene groups having 2 to 6 carbon atoms, propane-2,2-bis(4-phenylene), 1,4-xylylene, 1,3-xylylene or 1,2-xylylene; n is an integer of 1 to 6; 
         c) a radical reaction initiator; and 
         d) an organometallic catalyst; 
         wherein a hydroxyl value of the component b) isocyanate-reactive component is 200 mgKOH/g to 700 mgKOH/g, and a molar ratio of isocyanate groups to hydroxyl groups of the composition is 0.6 to 1.5. 
       
     
     
         2 . The polyurethane composition according to  claim 1 , wherein the component a) aliphatic isocyanate is one or more of the following: unblocked aliphatic diisocyanates, unblocked aliphatic polyisocyanates, unblocked alicyclic diisocyanates, unblocked alicyclic polyisocyanates, and polymers and prepolymers thereof. 
     
     
         3 . The polyurethane composition according to  claim 1 , wherein an isocyanate group content of the component a) isocyanate component is 10% by weight to 61% by weight, relative to the total weight of the component a) isocyanate component. 
     
     
         4 . The polyurethane composition according to  claim 1 , wherein a hydroxyl functionality of the component b1) organic polyol is 1.7 to 6. 
     
     
         5 . The polyurethane composition according to  claim 1 , wherein a hydroxyl value of the component b1) organic polyol is 20 mgKOH/g to 2000 mgKOH/g. 
     
     
         6 . The polyurethane composition according to  claim 1 , wherein the component b2) compound having the structure of formula I is one or more of the following: hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, hydroxypentyl methacrylate, hydroxyhexyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate and hydroxybutyl acrylate. 
     
     
         7 . The polyurethane composition according to  claim 1 , wherein the molar ratio of isocyanate groups to hydroxyl groups of the composition is 0.9 to 1.1. 
     
     
         8 . The polyurethane composition according to  claim 1 , wherein the polyurethane composition further comprises component e) a reaction accelerator, the reaction accelerator being one or more of the following: cobalt compounds and amine compounds. 
     
     
         9 . A polyurethane composite comprising a polyurethane resin matrix prepared from the polyurethane composition according to  claim 1  and a reinforcing material. 
     
     
         10 . The polyurethane composite according to  claim 9 , wherein the polyurethane resin matrix is prepared under a reaction condition in which the polyurethane composition is simultaneously subjected to radical polymerization reaction and to addition polymerization reaction of isocyanate groups and hydroxyl groups. 
     
     
         11 . The polyurethane composite according to  claim 9 , wherein the polyurethane composite is prepared by one or more of the following: pultrusion molding, winding molding, hand lay-up molding, injection molding, infusion and resin transfer molding, and vacuum infusion. 
     
     
         12 . A method for preparing a polyurethane composite comprising a polyurethane resin matrix and a reinforcing material, including preparing the polyurethane resin matrix under a reaction condition in which the polyurethane composition according to  claim 1  is simultaneously subjected to radical polymerization reaction and to addition polymerization reaction of isocyanate groups and hydroxyl groups. 
     
     
         13 . The method according to  claim 12 , wherein the method is one or more of the following: pultrusion molding, winding molding, hand lay-up molding, injection molding, infusion and resin transfer molding, and vacuum infusion. 
     
     
         14 . A method for preparing an article comprising forming a polyurethane composite according to  claim 9 . 
     
     
         15 . The method according to  claim 14 , wherein the article is selected from profiles, carriers, structural components for reinforcing pillars or lightweight structural components.